Field of the Invention
The present invention relates to solid milk to be dissolved in heated water for drinking, and method of making the same. More specifically, the present invention relates to solid milk having preferred solubility and strength.
Description of the Related Art
Powdered milk is food product whose shelf life is improved by removing almost all of the necessary moisture for the microbial growth from bovine milk and the like. Since the capacity and weight decrease by removing moisture, the powdered milk can be easily transported. Thus, the powdered milk has advantages in shelf life and transportation. The powdered milk has interspaces between milk powders, and the porosity of the milk powder is generally 60%-70%, so that it readily dissolves in heated water. However, the powdered milk requires measurement of proper quantity every time it is dissolved in heated water or the like. Also, upon measurement of the powdered milk or upon taking out the powdered milk, the powdered milk may spread. Therefore, solid milk that is the powdered milk made into solid state has been proposed (Japanese Utility Model Application Laid-Open Publication No. SHO49-130189 (see patent document 1 below), and Japanese Utility Model Application Laid-Open Publication No. SHO61-118280 (see patent document 2 below). However, it has not been easy to actually make the powdered milk into solid state and satisfy both of the strength and the solubility. Namely, even if the powdered milk is made into solid state, it has been easy to break and has been hard to handle. Moreover, the solid milk has smaller surface area compared to the powdered milk, so that it has been less soluble in the heated water.
When the powdered milk is actually pressured to be made into solid state, since the powdered milk is an emulsified substance, the emulsified state is destroyed by the pressure. Then the fat called “free fat” oozes from the powdered milk. The free fat readily oxidizes and destroys flavor of the powdered milk. Also, when the powdered milk is dissolved in the heated water, there is problem that excessive free fat floats on the water and aggregates. (This phenomenon is called “oil off”.) On the other hand, the Japanese Examined Patent Application Publication No. SHO49-4948 (see patent document 3 below) discloses “aggregated powdered milk”. The point that “the aggregated powdered milk is easily immersed and thus easily disintegrated when thrown into heated water to be dispersed and dissolved” is disclosed. However, the “aggregated powdered milk” in the publication is a mixture with sugar or glucose, so that it is “suitable for use in addition to coffee, tea, or the like”. Namely, the basic ingredient of the aggregated powdered milk is not only the powdered milk and it is not substituted for breast milk to be given to infants. The Japanese Examined Patent Application Publication No. SHO49-4948, considers the problems of the free fat and the like when only the powdered milk is used as the basic ingredient, thereby using the mixture of granulated powdered milk and sugar or glucose to make “aggregated powdered milk”. The powdered milk in a granulated state has a larger surface area compared to that in the solid state, so that its solubility is high even if the porosity of the granule itself is small.
The Japanese Examined Patent Application Publication No. SHO45-39018 (see patent document 4 below) discloses a technology similar to that of the above-mentioned Japanese Examined Patent Application Publication No. SHO49-4948. Namely, it is disclosed that in order to achieve readily soluble solid milk, the volume of interstice may be enlarged, and that there is problem of the free fat upon making the powdered milk into solid state. However, in the same document, since “there is a limit to the enlargement of a single particle of powdered milk” (column 2, line 30 of the same document), “the powdered milk is attached to sugar group for granulation and then molded and dried”, whereby “readily soluble solid milk with less free fat” is obtained (column 3, lines 13-15 of the same document). Namely, in the same document it is mentioned that the solid milk with only the powdered milk made into solid state cannot be obtained. Moreover, the solid milk described in the reference is obtained by attaching the sugar group to the powdered milk, so that the sugar group as a center core exists and the porosity is reduced. Also, the compositionally-homogeneous solid milk cannot be obtained.
The Japanese Examined Patent Application Publication No. SHO53-59066 discloses “solid milk tablet”. This solid milk tablet is a tablet of a high density having its fat component leached out on the surface and blocked from external air by the coating of the fat. Since high density tablet is desirable as the solid milk of the same document, its porosity is low.
Japanese patent No. 3044635 discloses “frozen milk”. The frozen milk includes a lot of water molecules, so that there is almost no air space.
Also, in the field of food product such as soup, solid food products to be dissolved by pouring hot water are known (Japanese Patent Application Laid-Open Publication No. HEI11-127823, Japanese Patent Application Laid-Open Publication No. 2004-49220, and Japanese Patent Application Laid-Open Publication No. 2004-49221) to which disintegrant is generally added. Also, since ingredients thereof are not the powdered milk, there is no problem such as free fat that is specific to the powdered milk. Namely, although the solid soup and the like are known, solid milk cannot be obtained by merely diverting these technologies in making the solid milk since the powdered milk that is the basic ingredient of the solid milk include a lot of fat.
Also, in the field of medicine, various “intraoral fast disintegrable tablets” readily soluble in the mouth have been developed (e.g. Japanese Patent Application Laid-Open Publication No. HE15-271054, Japanese Patent Application Laid-Open Publication No. HE18-291051, Japanese Patent Application Laid-Open Publication No. HE109-048726, Japanese Patent Application Laid-Open Publication No. 2000-95674, Japanese Patent Application Laid-Open Publication No. 2000-44463, Japanese Patent Application Laid-Open Publication No. 2001-89398, Japanese Patent Application Laid-Open Publication No. 2004-049220, and Japanese Patent No. 2650493). However, composition of medicine in general has a small rate in weight occupied by an active substance, so that a lot of additives such as vehicle other than the active substance can be blended, and the component design is relatively easy. Therefore, medicine, in general has a high strength, and needless to control its solubility by controlling the porosity. Also, medicine does not include a lot of fat as the powdered milk. Therefore, “fast disintegrable” technology in the “intraoral fast disintegrable tablet” cannot be diverted as is to the solid milk. Also, “intraoral fast disintegrable tablet” needs to dissolve rapidly by minimal water in the oral cavity. On the other hand, the solid milk is generally dissolved in heated water for drinking, but not taken directly into the mouth, so that fast solubility is not required as much as the “intraoral fast disintegrable tablet”.
[Patent document 1] Japanese Utility Model Application Laid-Open Publication No. SHO49-130189
[Patent document 2] Japanese Patent Application Laid-Open Publication No. SHO61-118280
[Patent document 3] Japanese Examined Patent Application Publication No. SHO49-4948
[Patent document 4] Japanese Examined Patent Application Publication No. SHO45-39018